xargs: restore correct behaviour of -n option

Since commit 1ff7002b1 (xargs: fix handling of quoted arguments, closes
11441) the -n option hasn't worked properly:

   $ echo 1 2 3 | xargs -n 1 echo
   1
   2

   3

   $

Because state is now remembered between calls to process_stdin() it's
necessary to update the state before any premature return.

2 files changed, 12 insertions, 1 deletions

diff --git a/findutils/xargs.c b/findutils/xargs.c
index 8d3a0027c..71350d470 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -388,6 +388,7 @@ static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
                         }
                 }
                 if (state == SPACE) {   /* word's delimiter or EOF detected */
+                        state = NORM;
                         if (q) {
                                 bb_error_msg_and_die("unmatched %s quote",
                                         q == '\'' ? "single" : "double");
@@ -408,7 +409,6 @@ static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
                         if (n_max_arg == 0) {
                                 goto ret;
                         }
-                        state = NORM;
                 }
                 if (p == buf) {
                         goto ret;
diff --git a/testsuite/xargs.tests b/testsuite/xargs.tests
index 855b33bc2..159f1ff69 100755
--- a/testsuite/xargs.tests
+++ b/testsuite/xargs.tests
@@ -48,6 +48,17 @@ testing "xargs argument line too long" \
         "seq 10000 99999 | sed -e 's/^/\"/' -e 's/$/\"/' | xargs echo | grep -o 99999; echo \$?" \
         "99999\n0\n" \
         "" ""
+
+testing "xargs -n1" \
+        "xargs -n1 echo" \
+        "1\n2\n3\n4\n5\n" \
+        "" "1 2 3 4 5\n"
+
+testing "xargs -n2" \
+        "xargs -n2 echo" \
+        "1 2\n3 4\n5\n" \
+        "" "1 2 3 4 5\n"
+
 SKIP=
 
 exit $FAILCOUNT